feat(tv-input): gamepad->keyboard bridge daemon + controller-navigable modals

- archipelago-gamepad-keys: evdev->uinput daemon (pure python3 stdlib) that
  mirrors any attached controller as a virtual keyboard — D-pad/stick to
  arrows, A/B to Enter/Escape, X/Y to Space/f, shoulders to Tab/Shift+Tab.
  The browser sees real keys, so controllers work inside EVERY app iframe
  (IndeeHub, Jellyfin…) with zero per-app code. Ships via the ISO splice and
  bootstrap self-heal (kiosk nodes only), hotplug via 5s rescans.
  Implements docs/tv-input-iframe-apps.md.
- useControllerNav: an open [role=dialog][aria-modal] owns navigation —
  focus is pulled inside, arrows move spatially between its controls, Enter
  activates, Escape stays with the modal's own close handling. One standard
  mapping for every modal.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/main.rs

@@ -391,6 +391,10 @@ async fn main() -> Result<()> {
     // boot-time ELD race that leaves HDMI silently unavailable).
     tokio::spawn(bootstrap::ensure_audio_stack());
 
+    // TV input: gamepad→keyboard bridge so controllers work inside every app
+    // iframe on kiosk nodes (docs/tv-input-iframe-apps.md).
+    tokio::spawn(bootstrap::ensure_gamepad_keys());
+
     // Pine voice: re-point IP-pinned Wyoming satellite entries (speakers) when
     // DHCP renumbering strands them — HA never re-resolves on its own.
     tokio::spawn(api::rpc::wyoming_satellite_keeper());